| /******************************************************************************* |
| * Copyright (c) 2005, 2006 IBM Corporation and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| |
| package org.eclipse.ui.internal.expressions; |
| |
| import org.eclipse.core.expressions.EvaluationResult; |
| import org.eclipse.core.expressions.Expression; |
| import org.eclipse.core.expressions.ExpressionInfo; |
| import org.eclipse.core.expressions.IEvaluationContext; |
| import org.eclipse.core.runtime.CoreException; |
| import org.eclipse.jface.viewers.ISelection; |
| import org.eclipse.ui.ISources; |
| import org.eclipse.ui.IWorkbenchWindow; |
| import org.eclipse.ui.SelectionEnabler; |
| |
| /** |
| * <p> |
| * An expression wrapper for the legacy {@link SelectionEnabler}. This emulates |
| * an {@link Expression} using an instance of <code>SelectionEnabler</code>. |
| * </p> |
| * <p> |
| * This class is not intended for use outside of the |
| * <code>org.eclipse.ui.workbench</code> plug-in. |
| * </p> |
| * |
| * @since 3.2 |
| */ |
| public final class LegacySelectionEnablerWrapper extends |
| WorkbenchWindowExpression { |
| |
| /** |
| * The seed for the hash code for all schemes. |
| */ |
| private static final int HASH_INITIAL = LegacySelectionEnablerWrapper.class |
| .getName().hashCode(); |
| |
| /** |
| * The enabler for this expression; never <code>null</code>. |
| */ |
| private final SelectionEnabler enabler; |
| |
| /** |
| * Constructs a new instance of <code>SelectionEnablerExpression</code>. |
| * |
| * @param enabler |
| * The enabler; must not be <code>null</code>. |
| * @param window |
| * The workbench window which must be active for this expression |
| * to evaluate to <code>true</code>; may be <code>null</code> |
| * if the window should be disregarded. |
| */ |
| public LegacySelectionEnablerWrapper(final SelectionEnabler enabler, |
| final IWorkbenchWindow window) { |
| super(window); |
| |
| if (enabler == null) { |
| throw new NullPointerException("There is no enabler"); //$NON-NLS-1$ |
| } |
| this.enabler = enabler; |
| } |
| |
| public final void collectExpressionInfo(final ExpressionInfo info) { |
| super.collectExpressionInfo(info); |
| info.markDefaultVariableAccessed(); |
| } |
| |
| protected final int computeHashCode() { |
| int hashCode = HASH_INITIAL * HASH_FACTOR + hashCode(getWindow()); |
| hashCode = hashCode * HASH_FACTOR + hashCode(enabler); |
| return hashCode; |
| } |
| |
| public final boolean equals(final Object object) { |
| if (object instanceof LegacySelectionEnablerWrapper) { |
| final LegacySelectionEnablerWrapper that = (LegacySelectionEnablerWrapper) object; |
| return equals(this.enabler, that.enabler) |
| && equals(this.getWindow(), that.getWindow()); |
| } |
| |
| return false; |
| } |
| |
| public final EvaluationResult evaluate(final IEvaluationContext context) |
| throws CoreException { |
| final EvaluationResult result = super.evaluate(context); |
| if (result == EvaluationResult.FALSE) { |
| return result; |
| } |
| |
| final Object defaultVariable = context |
| .getVariable(ISources.ACTIVE_CURRENT_SELECTION_NAME); |
| if (defaultVariable instanceof ISelection) { |
| final ISelection selection = (ISelection) defaultVariable; |
| if (enabler.isEnabledForSelection(selection)) { |
| return EvaluationResult.TRUE; |
| } |
| } |
| |
| return EvaluationResult.FALSE; |
| } |
| |
| public final String toString() { |
| final StringBuffer buffer = new StringBuffer(); |
| buffer.append("LegacySelectionEnablerWrapper("); //$NON-NLS-1$ |
| buffer.append(enabler); |
| buffer.append(','); |
| buffer.append(getWindow()); |
| buffer.append(')'); |
| return buffer.toString(); |
| } |
| } |